Electromechanical base converter

ABSTRACT

Instructional apparatus for representing numbers in a selected number system, normally other than the decimal system, and for indicating a given number in decimal form as well as the form into which it is converted by the apparatus. A master unit drives a series of identical slave unit modules, each of the slave units corresponding to one place of the number system. The master unit, under the control of a student or instructor, delivers a selected number of count pulses in serial fashion, such number being indicated by a decade counter on the master unit. The slave unit representing the units place counts the pulses and displays the number counted, and resets to zero after the units place fills. As the units place slave resets, it delivers a transfer command to a second slave unit representing the next higher order place. Successive transfer commands are counted and displayed by the second slave unit, which also resets after its place fills and delivers a transfer command to a third slave unit which operates in the same manner. As many slave units may be employed as dictated by the capacity desired. In each slave unit the counting function is executed by a stepper relay, and a base selector switch is provided so that the unit may be set to any one of several number systems, such as those of any base from 2 through 16.

United States Patent [151 3,681,859 Sandoval et al. [4 1 Aug. 8, 1972[54] ELECTROMECHANICAL BASE selected number system, -normally other thanthe CONVERTER I I decimal system, and for indicating a given number in[72] inventors: Antonio A. Sandoval, 3744 Benton decimal form as well asthe form into WhlCh it is con- Boulevard, Kansas City, Mo. 64128;

Donald J. Dunlavy, 5741 Grand,

Kansas City, M0. 641 13 Primary Examiner-Wm. H. Grieb AtrorneySchmidt,Johnson, Hovey & Williams verted by the apparatus. A master unit drivesa series of identical slave unit modules, each of the slave unitscorresponding to one place of the number system. The master unit, underthe control of a student or instructor, delivers'a selected. number ofcount pulses in serial fashion, such number being indicated by a decadecounter on the master unit. The slave unit representing the units placecounts the pulses and'displays the number counted, and resets to zeroafter the units.

place fills. As the units place slave resets, it delivers a transfercommand to a second slave unit representing the next higher order place.Successive transfer commands are counted and displayed by the secondslave unit, which also resets after its place fills and delivers atransfer command to a third slave unit which operates in the samemanner. As many slave units may 11 Claims, 2 Drawing Figures [57]ABSTRACT Instructional apparatus for representing numbers in a 24L Base2 Slave Slave Slave Master 36 341 Base 8 Slave Slave Slave 1ELECTROMECHANICAL BASE CONVERTER This invention relates to instructionalapparatus for familiarizing a student with the manner in which a givennumber is represented in a number system with which the student is notfamiliar.

An important object of the present invention is to provide apparatuscapable of displaying a number in a selected number system forinstructional purposes, wherein the various places of the number arerepresented by a series of individual modules, each of which indicatesthe figure in that place of the number, permitting the series torepresent as many places as desired in accordance with the number ofmodules utilized.

As a corollary to the foregoing object, it is an important aim of thisinvention to provide apparatus as aforesaid which employs a master unitto generate the number to be're'presented, and wherein said modulescomprise slave units responsive to the master unit output, and in whichsuch slave units maybe arranged in more than a single series in order tosimultaneously 7 represent the number in a plurality of number systems.

Another important object of this invention is to provide apparatus asaforesaid which converts a given number from the base 10 to the base ofthe selected number system, and which displays such number in both formsin order that the student may readily compare the numericalrepresentations of the two systems.

Still another important object of this invention is to provide apparatusas aforesaid which is of uncomplex design and employs reliable andinexpensive electromechanical components.

Furthermore, it is an important object of the invention to provide suchan apparatus in which the number system to be represented may beselected from a number of possible systems through the employment of astraightforward switching arrangement for base selection.

In the drawings:

FIG. 1 is a block diagram of the apparatus showing a master unit andslave unit modules in a two-series arrangement; and

FIG. 2 is an electrical schematic diagram of the apparatus, showing amaster unit and two slave units.

Referring initially to FIG. 1, a master unit is shown driving a firstseries of slave units 22 which, as indicated by the legend, representthe places of a base 2 or binary number system. The first slave unit 24represents the units place and has its input directly connected to theoutput of the master unit 20. The following slave unit 26 represents thenext higher order place and has its input connected to the output of thefirst slave unit 24. A third slave unit 28 is illustrated and representsthe third place of a number in binary form, and has its input connectedto the output of the slave unit 26. Accordingly, it is evident thattheseries of units 22 may be extended by merely adding additional slaveunits until the number of places are provided corresponding to thedesired capacity.

As will be discussed more fully hereinafter, the master unit 20 iscontrollable by an instructor or student and is operable to deliver aseries of count pulses, the number of which correspond to the number tobe displayed by the apparatus in a form determined by the selectednumber system. These pulses delivered by the master unit 20 are countedby the first slave unit 24 and, if sufficient in number to fill theunits place, the slave unit 24 resets to zero in response to the nextpulse occurring after the units place fills. As the unit 24 resets, itdelivers a transfer command at its output which is counted by the secondslave unit 26. Again, if the number is of sufficient size to more thanfill the second place represented by the slave unit 26, such unit,counts the transfer commands successfully delivered by the first slaveunit 24, ultimately resets to zero after the place fills, and delivers atransfer command at its output that is counted by the next slave unit28. It is to be understood that each of the slave units of the series 22displays the stored count so that the figure in each place may beobserved by the student. Furthermore, it is desirable to provide themaster unit 20 with a decade counter responsive to the count pulses sothat the student can also observe the conversion of the number from the'base 10 to the base 2 or other base that may be selected.

A second'series of slave units 30 is also illustrated in FIG. 1 andincludes a first unit 32 representing the units place and two additionalunits 34 and 36 representing higher order places. As indicated by thelegend, the series of units 30 may be set to the base 8 in order torepresent the number of count pulses in the octonary system. Asdiscussed above with respect to the series of units 22, the slave units32, 34 and 36 are connected in series input-to-output connectedrelationship with the capacity of the series being determined by thenumber of slave units employed in the series. It should be understoodthat all of the slave units depicted in FIG. 1 are modules of identicalconstruction, preferably of the plug-in type, with each module beingprovided with a base selector to permit the student or instructor toselect at will the number system to be represented. For properoperation, all of the slave units of a particular series must be set tothe same base, as will be appreciated from the detailed description tofollow.

Referring to FIG. 2, the master unit 20 is connected to suitable powerterminals 38 such as a convenience outlet from which 110 volts AC may beobtained. A pair of power leads 40 and 42 extend from the terminals 38into the master unit 20, both of these leads being carried to the slaveunits 24 and 26. The lead 40 is interrupted by an on-off switch 44 whichcontrols an electric motor 46. A single pole cam switch 48 is operatedby the shaft of the motor 46, the pole of the switch 48 being connectedto the lead 42 through the contacts of a push button count switch 50. Alead 52 is connected to the contact of the cam switch 48, and a solenoidoperated decade counter 54 is connected between the power lead 40 andthe lead 52.

The first slave unit 24 is provided with a connecting cable thatterminates in a plug schematically illustrated at 56, 56, 56". This plugis received by a female receptacle on the master unit 20 schematicallyillustrated at 58, 58', 58".

A stepper relay 60 in the slave unit 24 has an advance coil 62 connectedacross the plug terminals 56 and 56' through a voltage dropping resistor64. The armature of the advance coil 62 is mechanically connected to arotary switch element 66 which is engageable with a series of contactsidentified by the characters 0 through 9, and A through G. A reset coil68 is also mechanically connected. to the switch element 66 and, whenenergized, returns the element 66 to the position thereof illustrated inengagement with the contact.

A dial indicator 70 is diagrammatically illustrated and has a circulardial bearing the characters 0 through 9 and A through F. A dial pointer72 is rotatable with i the switch element 66 and may be directly mountedon the rotor shaft of the stepper switch assembly.

A base selector switch 74 has a manually adjustable rotor 76 engageablewith a series of contacts identified by the characters 2 through 9 and'Athrough G. The selector switch 74 is under the control of the instructoror student and thus a knob (not shown) would be provided on the slavemodule, together with the indicia 2-9 and A-G, to permit the operator toset the switch 74 at any desired position. It should be noted that thecontacts of the switch 74 are directly connected by leads 78 tocorresponding contacts of the stepper relay 60. The reset coil 68 isconnected between the rotor 76 and an extension 40a of the power lead40.

The output of the-first slave unit 24 is presented by lead 80 extendingfrom the rotor 76 of the base selector switch 74. The power leadextension 40a, the lead 80 and the power lead extension 42a terminate ata female receptacle on themodule schematically illustrated at 82, 82,82"", such receptacle receiving a plug 84, 84', 84" on a connectingcable extending from the second slave module 26. Accordingly, theterminal 84' of the male plug forms the input to the second slave unitand the power connections are continued via the power lead extensions40b and 42b. Since theconstruction of the two slave units 24 and 26 isidentical, the operating components of the second unit 26 are identifiedby the same reference numerals used hereinabove in the description ofthe first unit 24. Note that a female receptacle 86, 86', 86" is alsoprovided on the second unit 26 to provide a means of connecting thelatter to a succeeding slave unit, such as the unit 28 illustrated inFIG. 1. Both of the units 24 and 26 have a push button reset switch 88for effecting momentary energization of the respective reset coil 68.

OPERATION FIG. 2 shows in detail the circuit arrangement for place of abinary number, the base selector switches 74 of the two slave units 24and 26 being set to the base 2 as illustrated. Accordingly, for purposesof illustration, operation of the apparatus in converting a number fromthe base to the base 2 will first be discussed.

With the switch 44 closed the motor 46 in the master unit is incontinuous operation, causing repeated closing and opening of the camswitch 48, the latter serving as a mechanical pulser to produce countpulses on the lead 52 as represented by the wave form 90. Suchcountpulses are not produced, however, unless the count switch 50 is heldclosed by the operator. The two pulses shown in the wave form 90 areintended to illustrate periods of current conduction from the power lead42 through the lead 52; manifestly, a DC square wave would not beproduced if alternating current is supplied at the power terminals 38.

Each of the pulses is counted by the decade counter 54 and, assumingthat the operator wishes to represent the number 2, the count switch 50is held closed until the decade counter 54 registers 2. The operator, ofcourse, is familiar with the decimal system and thus readily recognizesthe readout of the decade counter 54.

The first count pulse fed to the slave unit 24 momentarily energizes thecoil 62 to advance the stepper switch element 66 one position where theelement 66 engages the 1 contact. The pointer 72 follows and alsoindicates l. The second pulse from the master unit 20 initiates asimilar action and would cause the switch element 66 to advanceto the 2contact and remain in this position, were it not for the fact that 2 isthe base of the number system to be represented, i.e. the number systemto which the apparatus is converting the decimal number 2. Since thebase selector switch 74 in the slave unit 24 is set in engagement withits 2 contact, the second step of the switch element 66 establisheselectrical continuity from the lead 52 through the connector 56', 58',the switch element 66, the lead 78' interconnecting the two 2 contacts,and the rotor 76 to the reset coil 68, causing the switch element 66 toreturn to the 0 position illustrated. Simultaneously, of course, thepointer 72' of the slave unit 24 also returns to the 0 indication. Sincethe count pulse is, of course, still maintaining the advance coil 62energized, the voltage dropping resistor 64 is necessary so that thefull voltage applied to the reset coil 68 will cause the armaturethereof to mechanically override the advance coil 62 and shift theswitch element 66 to the 0 position, in which it'remains once excitationis removed by the termination of the pulse.

The action just described above is necessitated since the numeral 1fills the units place in the binary or base 2 system. Numericinformation must be transferred to a higher order place if the number tobe represented is greater than can be handled by a particular lowerorder place. In this instance, therefore, the count is transferred tothe second slave unit 26 by virtue of the electrical connection of therotor 76 in the slave unit 24 with the advance coil 62 in the slave unit26, via the intervening lead 80 and the connector 82, 84. Accordingly,the transfer command referred to in the previous discussion of FIG. 1comprises pulse excitation appearing at the output of a particular slaveunit, such excitation causing both the resetting of that slave unit andcounting operation of the next succeeding slave unit.

In the foregoing example, it was desired to convert the number 2 to itsbinary equivalent which is the character 10, the 0 in the units placebeing displayed by the first slave unit 24 and the 1 in the next higherorder place being displayed by the second slave unit 26. This samescheme of operation is employed in the present invention regardless ofthe settings of the base selector switches 74 and the size of the numberto be converted and represented. The particular embodiment illustratedherein has slave units with sufficient numberrepresenting states toaccommodate bases from 2 through 16. The figures A, B, C, D, E, F and Gare equivalent to 10, ll, l2, 13, 14, 15 and 16 respectively in thedecimal system and are used for base 1 1 through base 16. The dialindicators read only through the figure F, since base G or 16 is thehighest base accommodated by the stepper switches and base selectorswitches illustrated.

Although for purposes of illustrating the concepts of this invention insimplified form a dial indicator 70 has been depicted in the schematicdrawing and specifically described above, it is to be understood that inmany instances, particularly where classroom demonstration to anumber ofstudents is involved, it maybe desirable to replace the dial indicatorwith an equivalent multiple light system to indicate respective numbers.For example, the indicator can be replaced with a rotary switch elementmounted on the shaft for rotary switch 66 and adapted to sequentiallyengage a series of contacts connected to corresponding indicator lightsforming a visual number display on the front panel of each slave unit24. The lights can be positioned in any desired relationship, as forexample in circular disposition or linearly, either vertically orhorizontally, so that as the rotary indicator switch element is shiftedfrom one light energizing contact to the next, the respective lights areactivated in serial order to present a visual change of the numberorder.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. Instructional apparatus for representing numbers in a selected numbersystem, said apparatus comprismg:

a master unit for providing a series of count pulses, and having anoutput and a control operable by a student or instructor for effectingthe delivery of a selected number of said pulses at said output; and

a plurality of slave units representing respective places of theselected number system, and including a first of said slave unitsrepresenting the units place and a second of said slave unitsrepresenting the next higher order place,

said first slave unit being coupled with the output of said master unitfor counting each of said pulses and displaying the number thereofcounted, and producing a transfer command when the next pulse is countedafter the units place fills,

said second slave unit being coupled with said first slave unit andresponsive to said transfer commands for counting the latter anddisplaying the number thereof counted,

each of said slave units having means resetting the unit to zero on thenext count after the place represented by the unit fills.

2. Apparatus as claimed in claim 1,

said selected number system being other than the decimal system,

said master unit being provided with a decade counter responsive to saidcount pulses for indicating the number thereof delivered at said output,whereby the apparatus converts the number selected by the student fromthe base to the base of the selected number system.

3. Apparatus as claimed in claim 1,

the resetting means of said first slave unit operating in response toeach of said transfer commands.

4. Apparatus as claimed in claim 1,

said second slave unit producing a transfer command for a subsequenthigher order slave unit when the next transfer command from the firstslave unit is counted after the place represented by said second slaveunit fills,

the resetting means of each of said first andsecond slave unitsoperating in response to each transfer command produced by therespective unit.

5. Apparatus as claimed in claim 1,

each of said slave units being provided with a base selector operable bythe student or instructor for setting the slave unit to the selectednumber system.

6. Apparatus as claimed in claim 5,

there being a second plurality of said slave units representingrespective places of another selected number system,

the first slave unit of said second plurality thereof being coupled withthe output of said master unit, whereby the same number of said countpulses is represented in two different number systems by the firstmentioned plurality and said second plurality of slave unitsrespectively.

7. Apparatus as claimed in claim 1,

' each of said slave units including a stepper relay having a series ofcontacts corresponding to numbers from zero through the base of theselected number system, a movable switch element engageable with saidcontacts, electrically responsive operating means coupled with saidelement for advancing the latter from contact to contact, and saidresetting means coupled with said element for returning the latter tothe zero contact,

the operating means of the relay of said first slave unit beingconnected with the output of said master unit and responsive to saidpulses,

said first slave unit further including circuit means connected with therelay contact thereof corresponding to said base for delivering saidtransfer command to the operating means of the relay of said secondslave unit and to the resetting means of said first slave unit tooperate the resetting means,

said second slave unit further including circuit means connecting therelay contact thereof corresponding to said base with the resettingmeans of said second slave unit for operation of the resetting meanswhen the switch element engages the last mentioned contact.

8. instructional apparatus for representing numbers in a selected numbersystem, said apparatus comprismg:

a master unit for providing a series of count pulses, and having anoutput and a control operable by a student or instructorfor effectingthe delivery of a selected number of said pulses at said output;

a plurality of slave units, each of which is provided with an input andan output and represents one place of the selected number system,

each slave unit having a plurality of numberrepresenting statessequentially assumed in response to pulse excitation received at itsinput,

each slave unit delivering a pulse command at its output when the stateis reached corresponding to the base of the selected number system, andbeing further provided with indicator means for displaying the numbercorresponding to the state thereof;

means for electrically coupling the input of the lowest order slave unitwith the output of the master unit for operation of the lowest orderslave unit in response to each of said count pulses; and

means for electrically coupling the input of each succeeding higherorder slave unit with the output of the preceding slave unit, wherebyeach higher order slave unit is operated when the preceding slave unitdelivers said command,

in a selected number system, said apparatus compris- 10 ing:

circuitry for providing a series of count pulses, and

.having an output and a control operable by a student or instructor foreffecting the delivery of a selected number of said pulses at saidoutput; a plurality of stepper relays, including a first and a secondstepper relay each having a series of contacts corresponding to numbersfrom zero through the base of the-selected number system, a movableswitch element engageable with said contacts, electrically responsiveoperating means coupled with said element for advancing the element fromcontact to contact, and electrically responsive reset means coupled withsaid element for returning the latter to the zero contact, the operatingmeans of said first relay being coupled with the output of saidcircuitry for advancement of the element of said first relay fromcontact to contact in response to said pulses; first indicator meansrepresenting the units place of the selected number system and coupledwith said first relay for indicating the number corresponding to thecontact position of the element thereof; first circuit means connectingthe reset means of said first relay and the operating means of saidsecond relay with the contact of said first relay corresponding to saidbase; means coupled with the element of said first relay for deliveringelectrical excitation thereto to effect energization of said reset meansof the first relay 7 and said operating 'means of the second relay whenthe element of said first relay engages the contact thereofcorresponding to said base, whereby said first relay is reset and theelement of said second relay advances one contact position; secondindicator means representing the next higher order place of the selectednumber system and coupled with said second relay for indicating thenumber corresponding to the contact position of the element thereof; and

second circuit means connecting the reset means of said second relaywiththe contact thereof corresponding to said base for energization ofthe last mentioned reset means upon engagement of the element of saidsecond relay with said contact corresponding to said base, whereby toreset said second relay when said higher order place fills.

10. Apparatus as claimed in claim 9,

said first circuit means including a first base selector switch having aplurality of contacts connected with corresponding contacts of saidfirst relay, and a switch component selectively engageable withindividual contacts of the selector switch to set the lglillS place tothe selectednu b er system, sai second circuit means inc udmg a secondbase

1. Instructional apparatus for representing numbers in a selected numbersystem, said apparatus comprising: a master unit for providing a seriesof count pulses, and having an output and a control operable by astudent or instructor for effecting the delivery of a selected number ofsaid pulses at said output; and a plurality of slave units representingrespective places of the selected number system, and including a firstof said slave units representing the units place and a second of saidslave units representing the next higher order place, said first slaveunit being coupled with the output of said master unit for counting eachof said pulses and displaying the number thereof counted, and producinga transfer command when the next pulse is counted after the units placefills, said second slave unit being coupled with said first slave unitand responsive to said transfer commands for counting the latter anddisplaying the number thereof counted, each of said slave units havingmeans resetting the unit to zero on the next count after the placerepresented by the unit fills.
 2. Apparatus as claimed in claim 1, saidselected number system being other than the decimal system, said masterunit being provided with a decade counter responsive to said countpulses for indicating the number thereof delivered at said output,whereby the apparatus converts the number selected by the student fromthe base 10 to the base of the selected number system.
 3. Apparatus asclaimed in claim 1, the resetting means of said first slave unitoperating in response to each of said transfer commands.
 4. Apparatus asclaimed in claim 1, said second slave unit producing a transfer commandfor a subsequent higher order slave unit when the next transfer commandfrom the first slave unit is counted after the place represented by saidsecond slave unit fills, the resetting means of each of said first andsecond slave units operating in response to each transfer commandproduced by the respective unit.
 5. Apparatus as claimed in claim 1,each of said slave units being provided with a base selector operable bythe student or instructor for setting the slave unit to the selectednumber system.
 6. Apparatus as claimed in claim 5, there being a secondplurality of said slave units representing respective places of anotherselected number system, the first slave unit of said second pluralitythereof being coupled with the output of said master unit, whereby thesame number of said count pulses is represented in two different numbersystems by the first mentioned plurality and said second plurality ofslave units respectively.
 7. Apparatus as claimed in claim 1, each ofsaid slave units including a stepper relay having a series of contactscorresponding to numbers from zero through the base of the selectednumber system, a movable switch element engageable with said contacts,electrically responsive operating means coupled with said element foradvancing the latter from contact to contact, and said resetting meanscoupled with said element for returning the latter to the zero contact,the operating means of the relay of said first slave unit beingcoNnected with the output of said master unit and responsive to saidpulses, said first slave unit further including circuit means connectedwith the relay contact thereof corresponding to said base for deliveringsaid transfer command to the operating means of the relay of said secondslave unit and to the resetting means of said first slave unit tooperate the resetting means, said second slave unit further includingcircuit means connecting the relay contact thereof corresponding to saidbase with the resetting means of said second slave unit for operation ofthe resetting means when the switch element engages the last mentionedcontact.
 8. Instructional apparatus for representing numbers in aselected number system, said apparatus comprising: a master unit forproviding a series of count pulses, and having an output and a controloperable by a student or instructor for effecting the delivery of aselected number of said pulses at said output; a plurality of slaveunits, each of which is provided with an input and an output andrepresents one place of the selected number system, each slave unithaving a plurality of number-representing states sequentially assumed inresponse to pulse excitation received at its input, each slave unitdelivering a pulse command at its output when the state is reachedcorresponding to the base of the selected number system, and beingfurther provided with indicator means for displaying the numbercorresponding to the state thereof; means for electrically coupling theinput of the lowest order slave unit with the output of the master unitfor operation of the lowest order slave unit in response to each of saidcount pulses; and means for electrically coupling the input of eachsucceeding higher order slave unit with the output of the precedingslave unit, whereby each higher order slave unit is operated when thepreceding slave unit delivers said command, each slave unit having resetmeans responsive to delivery of said command by the unit for returningthe latter to a normal, zero-representing state.
 9. Instructionalapparatus for representing numbers in a selected number system, saidapparatus comprising: circuitry for providing a series of count pulses,and having an output and a control operable by a student or instructorfor effecting the delivery of a selected number of said pulses at saidoutput; a plurality of stepper relays, including a first and a secondstepper relay each having a series of contacts corresponding to numbersfrom zero through the base of the selected number system, a movableswitch element engageable with said contacts, electrically responsiveoperating means coupled with said element for advancing the element fromcontact to contact, and electrically responsive reset means coupled withsaid element for returning the latter to the zero contact, the operatingmeans of said first relay being coupled with the output of saidcircuitry for advancement of the element of said first relay fromcontact to contact in response to said pulses; first indicator meansrepresenting the units place of the selected number system and coupledwith said first relay for indicating the number corresponding to thecontact position of the element thereof; first circuit means connectingthe reset means of said first relay and the operating means of saidsecond relay with the contact of said first relay corresponding to saidbase; means coupled with the element of said first relay for deliveringelectrical excitation thereto to effect energization of said reset meansof the first relay and said operating means of the second relay when theelement of said first relay engages the contact thereof corresponding tosaid base, whereby said first relay is reset and the element of saidsecond relay advances one contact position; second indicator meansrepresenting the next higher order place of the selected number systemand coupled with said second relay for iNdicating the numbercorresponding to the contact position of the element thereof; and secondcircuit means connecting the reset means of said second relay with thecontact thereof corresponding to said base for energization of the lastmentioned reset means upon engagement of the element of said secondrelay with said contact corresponding to said base, whereby to resetsaid second relay when said higher order place fills.
 10. Apparatus asclaimed in claim 9, said first circuit means including a first baseselector switch having a plurality of contacts connected withcorresponding contacts of said first relay, and a switch componentselectively engageable with individual contacts of the selector switchto set the units place to the selected number system, said secondcircuit means including a second base selector switch having a pluralityof contacts connected with corresponding contacts of said second relay,and a switch component selectively engageable with individual contactsof the second selector switch to set the higher order place to theselected number system.
 11. Apparatus as claimed in claim 9, the switchelement of each of said relays including a rotor, each of said indicatormeans including a pointer mechanically connected with the rotor of therespective relay, and an indicia bearing dial operably associated withsaid pointer.